As plastic is a petroleum based product these small particles act as persistent organic polluters, which means that they form a sponge attracting toxins such as insecticides and pesticides.

CNN: STORY HIGHLIGHTS

And for the first time, plants using the worst chemicals--substances such as mercury, labeled persistent bioaccumulative toxins--would be able to use the short form, so long as they use less than 500 pounds of that chemical and release none into the environment.

FORBES: Toxic Neighbors?